a = [x*x for x in range(2,101) if x % 2 == 0]
b = a[::-1]
c = a[::2]
d = a[::-3]
# print('正向输出',a)
# print('逆向输出',b)
# print('跳过一个输出',c)
# print('跳过两个输出',d)
print(a[:])
